Traits

Flyby (Scaled Wings only). The sea serpent doesn’t provoke Opportunity Attacks when it flies out of an enemy’s reach.

Actions

Multiattack. The sea serpent makes a number of attacks equal to half this spell’s level (rounded down).

Allure (Glowing Lantern only). The sea serpent causes a lantern hanging from one of its fins to glow eerily. Wisdom Saving Throw: DC equals your spell save DC, each creature in a 30-foot Emanation originating from the sea serpent. Failure: The target is Charmed by the sea serpent until the start of its next turn. Creatures have Advantage on the saving throw if the sea serpent has dealt damage to them already this turn, and the Charmed condition ends immediately if the sea serpent deals damage to a creature Charmed by this ability.

Inhale (Monstrous Mouth only). Strength Saving Throw: DC equals your spell save DC, each creature in a 15-foot Cone. Failure: 1d6 + the spell’s level Psychic damage and the creature is pulled 5 feet straight toward it or, if the creature is already within 5 feet of the sea serpent, it takes an additional 2d6 Piercing damage. Success: Half damage.

Bite. Melee Attack Roll: Bonus equals your spell attack modifier, reach 5 ft. Hit: 1d6 + 3 + the spell’s level Piercing damage and the creature has the Grappled condition (escape DC equals your spell save DC). The Grappled condition ends if the sea serpent bites a different creature.

Thrash. Melee Attack Roll: Bonus equals your spell attack modifier, reach 10 ft. Hit: 1d10 + 3 + the spell’s level Bludgeoning damage and the target is pushed 5 feet away from the sea serpent.